1. Field of the Invention
This invention relates to a car motor diving apparatus used to drive, for example, an engine starter motor, an electric power steering motor, and a wiper motor.
2. Description of the Related Art
An electromechanical energy converting section is used to drive the engine starter motor, effect electric power steering, drive the wipers, and open and close the windows. The electromechanical energy converting section receives the output voltage from a main storage battery (hereinafter, referred to as the battery) and then drives the above motors.
Under the leadership of European countries, use of a higher-voltage car battery is being planned. Use of a higher-voltage car battery means that the present output voltage of 12 V is raised to an output voltage of, for example, 36 V or 42 V. Use of such a higher battery output voltage enables wires to be laid with a small amount of copper in supplying the same power in, for example, an EPS. From this, use of higher voltages is expected to lead to resource saving and energy saving.
On the other hand, car manufactures need electromechanical energy converting sections, including motors, inverters, and converters, that meet various voltage specifications according to batteries differing in output voltage. That is, a battery with an output voltage of 12 V requires an electromechanical converting section composed of a motor, inverter, or converter according to specifications complying with the 12-volt output.
Furthermore, a battery with an output voltage of 36 V or 42 V needs an electromechanical converting section composed of a motor, inverter, or converter according to specifications complying with the 36-volt or 42-volt output.
A car is provided with a plurality of electric circuit systems and driving systems that operate on different voltages. A step-up circuit is connected to each of the electric circuit systems and driving system.
Specifically, the step-up circuit is for stepping up or down the output voltage of an alternator and supplying the stepped-up or stepped-down voltage to the corresponding electric circuit system or driving system. That is, each of the stepped-up or stepped-down voltages is used as the power supply for the corresponding electric circuit system and driving system.
This mechanism is a power supply apparatus which steps up or down the output voltage of the alternator instead of providing a plurality of batteries differing in output voltage, and drives a plurality of electric circuit systems and driving systems differing in operating voltage.
The alternator generates electricity according to the car speed when the car is running. When the car is running at high speeds, the alternator generates very high voltages, whereas it does not generate much electricity when it is moving at low speeds.
Therefore, the output voltage of the alternator has to be stepped up or down before it is supplied to a plurality of electric circuit systems and driving systems.
When the car using the output voltage of the alternator as a power supply is standing (or idling), the alternator generates a little electricity. Consequently, the alternator cannot be used in an electric circuit system or driving system that requires a large current, for example, a motor.
With this backdrop, there is a time when a battery with an output voltage of 12 V and a battery with an output voltage of 36 V or 42 V are present in a mixed manner in the course of realizing a plan to make a higher-voltage battery.
Accordingly, there have been demands that, even when an electromechanical energy converting unit complies with 36-volt or 42-volt output specifications, it should be compatible with a battery with an output voltage of 12 V without changing the specification of the electromechanical energy converting unit.
The object of the present invention is to provide a car motor driving apparatus capable of using batteries different in output voltage with the movement toward an electromechanical energy converting unit conforming to higher-voltage specifications.
According to a major aspect of the present invention, there is provided a car motor driving apparatus comprising: an electromechanical energy converting section for driving various motors in a car by applying specific voltages to the motors; a main storage battery for supplying a voltage to the electromechanical energy converting section; and a step-up unit connected between the main storage battery and the electromechanical energy converting section in such a manner that it is switched to either the main storage battery or the electromechanical energy converting section according to the output voltage of the main storage battery.
In the car motor driving apparatus, the step-up unit is disconnected when the main storage battery with an output voltage corresponding to the driving voltage of the electromechanical energy converting section is installed, whereas it is connected when the main storage battery with a lower output voltage than the driving voltage of the electromechanical energy converting section is installed.
Furthermore, the car motor driving apparatus further comprising control means for disconnecting the step-up unit from between the main storage battery and the electromechanical energy converting section when the output voltage gets to correspond to the driving voltage of the electromechanical energy converting section as a result of the replacement of the main storage battery and connecting the main storage battery to the electromechanical energy converting section.
According to a major aspect of the present invention, there is provided a car motor driving apparatus comprising: an electromechanical energy converting section for driving various motors in a car by applying specific voltages to the motors; a main storage battery for supplying a voltage to the electromechanical energy converting section; a step-up unit for stepping up the output voltage of the main storage battery to the driving voltage of the electromechanical energy converting section when the output voltage of the main storage battery is lower than the driving voltage of the electromechanical energy converting section; and a selector switch for connecting the main storage battery to the electromechanical energy converting section when the output voltage of the main storage battery corresponds to the driving voltage of the electromechanical energy converting section, whereas connecting the step-up unit between the main storage battery and the electromechanical energy converting section when the output voltage of the main storage battery is lower than the driving voltage of the electromechanical energy converting section.
In the car motor driving apparatus, the main storage battery produces an output voltage of 12 V and an output voltage of 36 V or 42 V.
Furthermore, in the car motor driving apparatus, the step-up unit is modularized and is capable of being installed on and removed from a desired part of the body of the car.
Additionally, in the car motor driving apparatus, the electromechanical energy converting section is composed of an inverter section for performing direct-current-to-direct-current conversion and a control circuit section for controlling at least the inverter section, the inverter section and control circuit section being modularized and capable of being installed on and removed from a desired part of the body of the car.
Moreover, in the car motor driving apparatus, the various motors include an engine starter, an electric power steering motor, a wiper motor, a window motor, and an air conditioner motor in the car.
Furthermore, in the car motor driving apparatus, the step-up unit is capable of being installed and removed from between the main storage battery and the electromechanical energy converting section.
According to a major aspect of the present invention, there is provided a car motor driving apparatus comprising: a plurality of electromechanical energy converting sections for driving at least an engine starter, an electric power steering motor, a wiper motor, a window motor, and an air conditioner motor in a car by applying specific voltages to the motors; a main storage battery for supplying a voltage to the electromechanical energy converting section; a step-up unit for stepping up the output voltage of the main storage battery to the driving voltage of the electromechanical energy converting section when the output voltage of the main storage battery is lower than the driving voltage of the electromechanical energy converting section; and a selector switch for connecting the main storage battery to the electromechanical energy converting section when the output voltage of the main storage battery corresponds to the driving voltage of the electromechanical energy converting section, whereas connecting the step-up unit between the main storage section and the electromechanical energy converting section when the output voltage of the main storage battery is lower than the driving voltage of the electromechanical energy converting section, wherein the electromechanical energy converting section is composed of an inverter section for performing direct-current-to-direct-current conversion and a control circuit section for controlling at least the inverter section, the inverter section and control circuit section being modularized and capable of being installed on and removed from a desired part of the body of the car.
According to a major aspect of the present invention, there is provided a car motor driving apparatus comprising: a plurality of electromechanical energy converting sections for driving at least an engine starter, an electric power steering motor, a wiper motor, a window motor, and an air conditioner motor in a car by applying specific voltages to the motors; a main storage battery for supplying a voltage to the electromechanical energy converting section; and a step-up unit which is provided between the main storage battery and the electromechanical energy converting section and steps up the output voltage of the main storage battery to the driving voltage of the electromechanical energy converting section when the output voltage of the main storage battery is lower than the driving voltage of the electromechanical energy converting section, and which is removed from between the main storage battery and the electromechanical energy converting section when the output voltage of the main storage battery is higher than the driving voltage of the electromechanical energy converting section, wherein the electromechanical energy converting section is composed of an inverter section for performing direct-current-to-direct-current conversion and a control circuit section for controlling at least the inverter section, the inverter section and control circuit section being modularized and capable of being installed on and removed from a desired part of the body of the car, and the step-up unit is capable of being installed and removed from between the main storage battery and the electromechanical energy converting section.
According to the present invention, it is possible to provide a car motor driving apparatus capable of coping with a battery of any potential.
Furthermore, in the present invention, the main storage battery is connected directly to the electromechanical energy converting section in a car carrying the electromechanical energy converting section with a high driving voltage of 36 V or 42 V, whereas a step-up unit is connected between the main storage battery and the electromechanical energy converging section in a car carrying the electromechanical energy converting section with a low driving voltage of 12 V. This way of connection enables main storage batteries complying with those voltage specifications to be used even during the time when a main storage battery with an output voltage of 12 V and a main storage battery with an output voltage of 36 V or 42 V are present in a mixed manner.
Moreover, in the present invention, since the step-up unit is capable of being installed and removed from between the main storage battery and the electromechanical energy converting section, the replacement of the main storage battery with an output voltage of 12 V with a main storage battery with an output voltage of 36 V can be dealt with by just removing the step-up unit.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.